bpo-46323: _ctypes.CFuncPtr fails if _argtypes_ is too long (GH-31188)

bpo-46323: _ctypes.CFuncPtr fails if _argtypes_ is too long (GH-31188)

ctypes.CFUNCTYPE() and ctypes.WINFUNCTYPE() now fail to create the
type if its "_argtypes_" member contains too many arguments.
Previously, the error was only raised when calling a function.

Change also how CFUNCTYPE() and WINFUNCTYPE() handle KeyError to
prevent creating a chain of exceptions if ctypes.CFuncPtr raises an
error.